Sentences with phrase «radiative forcing changes over»

For this fit, we find that the contributions to the GMAST rise are in almost the same ratios as the radiative forcing changes over the interval.

The model results (which are based on driving various climate models with estimated solar, volcanic, and anthropogenic radiative forcing changes over this timeframe) are, by in large, remarkably consistent with the reconstructions, taking into account the statistical uncertainties.

Not exact matches

China's stated aim of improving air quality over the coming years would change this radiative forcing, leading to a rather counter-intuitive consequence; the increase in China's contribution to global warming.

Near - global satellite aerosol data imply a negative radiative forcing due to stratospheric aerosol changes over this period of about — 0.1 W / m2, reducing the recent global warming that would otherwise have occurred.

We can estimate this independently using the changes in ocean heat content over the last decade or so (roughly equal to the current radiative imbalance) of ~ 0.7 W / m2, implying that this «unrealised» forcing will lead to another 0.7 × 0.75 ºC — i.e. 0.5 ºC.

«They're pretty evenly distributed across the atmosphere,» said Stephen Montzka, a NOAA scientist who monitors global changes in HFCs and studies their radiative forcing effects over time.

In fact, there is reasonably compelling evidence that changes in drought in the western U.S. over the past millennium may, in large part, reflect the forced response of ENSO to past volcanic and solar radiative forcing.

Given those assumptions, looking at the forcing over a long - enough multi-decadal period and seeing the temperature response gives an estimate of the transient climate response (TCR) and, additionally if an estimate of the ocean heat content change is incorporated (which is a measure of the unrealised radiative imbalance), the ECS can be estimated too.

[Response: To pre-empt some mutual incomprehension, note that industrial CO2 rises are certainly an anthropgenic forcing and not a response (see here and here), but clearly CO2 changes over glacial - interglacial cycles is both a response (to Milankovitch - driven changes) and a forcing (since the additional radiative forcing from CO2 is about a third of that needed to keep the ice ages as cold as they are — see here).

http://www.springerlink.com/content/lm0024kv72t3841w/ «The simulated magnitude of hydrological changes over land are much larger when compared to changes over oceans in the recent marine cloud albedo enhancement study since the radiative forcing over land needed (− 8.2 W m − 2) to counter global mean radiative forcing from a doubling of CO2 (3.3 W m − 2) is approximately twice the forcing needed over the oceans (− 4.2 W m − 2).

The effect of band widenning is a reduction in net upward LW flux (this is called the radiative forcing), which is proportional to a change in area under the curve (a graph of flux over the spectrum); the contribution from band widenning is equal to the amount by which the band widens (in units ν) multiplied by - Fνup (CO2).

It presents a significant reinterpretation of the region's recent climate change origins, showing that atmospheric conditions have changed substantially over the last century, that these changes are not likely related to historical anthropogenic and natural radiative forcing, and that dynamical mechanisms of interannual and multidecadal temperature variability can also apply to observed century - long trends.

The climate sensitivity is defined as the equilibrated change in global mean surface air temperature (SAT) for a given change in radiative forcing and has been a major focus of climate research over the last three decades.

The current role of methane looms large, he says, contributing over 40 percent of current radiative forcing from all greenhouse gases, based on the latest science from the Intergovernmental Panel on Climate Change.

The albedo change resulting from the snowline retreat on land is similarly large as the retreat of sea ice, so the combined impact could be well over 2 W / sq m. To put this in context, albedo changes in the Arctic alone could more than double the net radiative forcing resulting from the emissions caused by all people of the world, estimated by the IPCC to be 1.6 W / sq m in 2007 and 2.29 W / sq m in 2013.»

The decadal changes in TOA flux associated with ENSO and the PDO suggest that the longer term patterns associated with changing SST over centuries to millennia are associated with significant but unknowable changes in cloud radiative forcing.

Fortunately, the negative and positive forcings are roughly equal and cancel each other out, and the natural forcings over the past half century have also been approximately zero (Meehl 2004), so the radiative forcing from CO2 alone gives us a good estimate as to how much we expect to see the Earth's surface temperature change.

The report not only compared the changes in radiative forcing over the last 20 years, it also highlighted the quantities of greenhouse gases in the atmosphere.

Radiative forcing from methane makes up over 15 % of the recorded change with 60 % of methane production coming from human activities.

Here we show that accounting for recent cooling in the eastern equatorial Pacific reconciles climate simulations and observations.We present a novel method of uncovering mechanisms for global temperature change by prescribing, in addition to radiative forcing, the observed history of sea surface temperature over the central to eastern tropical Pacific in a climate model.

Anomalies in the volcanic - aerosol induced global radiative heating distribution can force significant changes in atmospheric circulation, for example, perturbing the equator - to - pole heating gradient (Stenchikov et al., 2002; Ramaswamy et al., 2006a; see Section 9.2) and forcing a positive phase of the Arctic Oscillation that in turn causes a counterintuitive boreal winter warming at middle and high latitudes over Eurasia and North America (Perlwitz and Graf, 2001; Stenchikov et al., 2002, 2004, 2006; Shindell et al., 2003b, 2004; Perlwitz and Harnik, 2003; Rind et al., 2005; Miller et al., 2006).

Based on the IPCC, 2001 findings, this is a reasonable estimate of the change over the recent decades in the atmospheric radiative forcing).

Ice albedo feedback change is mainly limited to high latitude NH * land * during deglaciation, and its effects — though strong — are limited compared to those of a radiative forcing over the global ocean.

The theory is that climate will warm in proportion to changes in radiative forcing over time (+ equilibrium «pipeline» warming).

This is achieved through the study of three independent records, the net heat flux into the oceans over 5 decades, the sea - level change rate based on tide gauge records over the 20th century, and the sea - surface temperature variations... We find that the total radiative forcing associated with solar cycles variations is about 5 to 7 times larger than just those associated with the TSI variations, thus implying the necessary existence of an amplification mechanism, although without pointing to which one.

Counters: «Once the model finishes producing the data representing how radiative forcing has changed over time, we can then go back and analyze that data to see how the climate system in terms of temperature and other factors will change based on empirical relationships between atmospheric factors and changes in temperature.»

Once the model finishes producing the data representing how radiative forcing has changed over time, we can then go back and analyze that data to see how the climate system in terms of temperature and other factors will change based on empirical relationships between atmospheric factors and changes in temperature.

Temperature changes over time can be affected by various factors, including changes in Solar Radiation (SR) and in the Radiative Forcing (RF) attributable to rising atmospheric concentrations of anthropogenic greenhouse gases.

Near - global satellite aerosol data imply a negative radiative forcing due to stratospheric aerosol changes over this period of about — 0.1 watt per square meter, reducing the recent global warming that would otherwise have occurred.

In terms of future radiative forcing and global - mean temperature changes over 1990 — 2100 they correspond to uncertainties of at least ± 0.2 Wm − 2 and ± 0.1 ° C, respectively.

The ISCCP - FD and ERBE data show cloud changes dominating over any possible change in radiative forcing caused by greenhouse gases.

Over several centuries, it may be possible to observe the effect of these orbital parameters, however for the prediction of climate change in the 21st century, these changes will be far less important than radiative forcing from greenhouse gases.»

«Despite a wide range of climate sensitivity (i.e. the amount of surface temperature increase due to a change in radiative forcing, such as an increase of CO2) exhibited by the models, they all yield a global average temperature change very similar to that observed over the past century.

Because all 2013 Intergovernmental Panel on Climate Change scenarios — except Representative Concentration Pathway 2.6 (RCP2.6), which leads to the total radiative forcing of greenhouse gases of 2.6 W m − 2 in 2100 — imply that cumulative carbon emission will exceed 1,000 Gt in the twenty - first century, our results suggest that anthropogenic interference will make the initiation of the next ice age impossible over a time period comparable to the duration of previous glacial cycles.»

Here, we present an explanation for time - invariant land — sea warming ratio that applies if three conditions on radiative forcing are met: first, spatial variations in the climate forcing must be sufficiently small that the lower free troposphere warms evenly over land and ocean; second, the temperature response must not be large enough to change the global circulation to zeroth order; third, the temperature response must not be large enough to modify the boundary layer amplification mechanisms that contribute to making φ exceed unity.

Comparing the trend in global temperature over the past 100 - 150 years with the change in «radiative forcing» (heating or cooling power) from carbon dioxide, aerosols and other sources, minus ocean heat uptake, can now give a good estimate of climate sensitivity.

Anomalies in the volcanic - aerosol induced global radiative heating distribution can force signifi cant changes in atmospheric circulation, for example, perturbing the equator - to - pole heating gradient (Stenchikov et al., 2002; Ramaswamy et al., 2006a; see Section 9.2) and forcing a positive phase of the Arctic Oscillation that in turn causes a counterintuitive boreal winter warming at middle and high latitudes over Eurasia and North America (Perlwitz and Graf, 2001; Stenchikov et al., 2002,2004, 2006; Shindell et al., 2003b, 2004; Perlwitz and Harnik, 2003; Rind et al., 2005; Miller et al., 2006).

(trouble is 35 is for carbon dioxide concentration, and 65 is for forcing, so if that's the calculation it was indeed a typo in a spreadsheet) Actually CO2 as a percentage of all radiative forcing would be: 43/65 * 100 = 66 % You messed up the link (I think) so that it actually leads back to this page rather than the FAQ section http://illconsidered.blogspot.com/2006/02/whats-wrong-with-warm-weather.html Never mind, as you know, I don't think the costs imposed by that change are large, not as long as sea level rise is only 50 cm over a hundred years (and the midpoint for the scenarios I consider most policy relevant, ie those excluding lots of coal burning after 2050, is somewhat lower still) and the change in «weather extremes» largely amounts to nothing more than what would be expected from moving south a few hundred kilometres.

We present a novel method of uncovering mechanisms for global temperature change by prescribing, in addition to radiative forcing, the observed history of sea surface temperature over the central to eastern tropical Pacific in a climate model.

Remember that the Arctic is an ocean surrounded by land, and temperatures over land change relatively quickly in response to a radiative forcing.